cocos-enhance-kit/engine/cocos2d/animation/motion-path-helper.js
2022-06-25 00:23:03 +08:00

416 lines
12 KiB
JavaScript

/****************************************************************************
Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.
https://www.cocos.com/
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated engine source code (the "Software"), a limited,
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not use Cocos Creator software for developing other software or tools that's
used for developing games. You are not granted to publish, distribute,
sublicense, and/or sell copies of Cocos Creator.
The software or tools in this License Agreement are licensed, not sold.
Xiamen Yaji Software Co., Ltd. reserves all rights not expressly granted to you.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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****************************************************************************/
var DynamicAnimCurve = require('./animation-curves').DynamicAnimCurve;
var computeRatioByType = require('./animation-curves').computeRatioByType;
var bezier = require('./bezier').bezier;
var binarySearch = require('../core/utils/binary-search').binarySearchEpsilon;
var v2 = cc.v2;
function Curve (points) {
this.points = points || [];
this.beziers = [];
this.ratios = [];
this.progresses = [];
this.length = 0;
this.computeBeziers();
}
Curve.prototype.computeBeziers = function () {
this.beziers.length = 0;
this.ratios.length = 0;
this.progresses.length = 0;
this.length = 0;
var bezier;
for (var i = 1; i < this.points.length; i++) {
var startPoint = this.points[i - 1];
var endPoint = this.points[i];
bezier = new Bezier();
bezier.start = startPoint.pos;
bezier.startCtrlPoint = startPoint.out;
bezier.end = endPoint.pos;
bezier.endCtrlPoint = endPoint.in;
this.beziers.push(bezier);
this.length += bezier.getLength();
}
var current = 0;
for (var i = 0; i < this.beziers.length; i++) {
bezier = this.beziers[i];
this.ratios[i] = bezier.getLength() / this.length;
this.progresses[i] = current = current + this.ratios[i];
}
return this.beziers;
};
function Bezier () {
this.start = v2();
this.end = v2();
this.startCtrlPoint = v2(); // cp0, cp1
this.endCtrlPoint = v2(); // cp2, cp3
}
// Get point at relative position in curve according to arc length
// - u [0 .. 1]
Bezier.prototype.getPointAt = function ( u ) {
var t = this.getUtoTmapping( u );
return this.getPoint( t );
};
// Get point at time t
// - t [0 .. 1]
Bezier.prototype.getPoint = function ( t ) {
var x = bezier(this.start.x, this.startCtrlPoint.x, this.endCtrlPoint.x, this.end.x, t);
var y = bezier(this.start.y, this.startCtrlPoint.y, this.endCtrlPoint.y, this.end.y, t);
return new v2(x, y);
};
// Get total curve arc length
Bezier.prototype.getLength = function () {
var lengths = this.getLengths();
return lengths[ lengths.length - 1 ];
};
// Get list of cumulative segment lengths
Bezier.prototype.getLengths = function ( divisions ) {
if ( ! divisions ) divisions = (this.__arcLengthDivisions) ? (this.__arcLengthDivisions): 200;
if ( this.cacheArcLengths
&& ( this.cacheArcLengths.length === divisions + 1 )) {
//console.log( "cached", this.cacheArcLengths );
return this.cacheArcLengths;
}
var cache = [];
var current, last = this.getPoint( 0 ), vector = v2();
var p, sum = 0;
cache.push( 0 );
for ( p = 1; p <= divisions; p ++ ) {
current = this.getPoint ( p / divisions );
vector.x = last.x - current.x;
vector.y = last.y - current.y;
sum += vector.mag();
cache.push( sum );
last = current;
}
this.cacheArcLengths = cache;
return cache; // { sums: cache, sum:sum }; Sum is in the last element.
};
Bezier.prototype.getUtoTmapping = function ( u, distance ) {
var arcLengths = this.getLengths();
var i = 0, il = arcLengths.length;
var targetArcLength; // The targeted u distance value to get
if ( distance ) {
targetArcLength = distance;
} else {
targetArcLength = u * arcLengths[ il - 1 ];
}
//var time = Date.now();
// binary search for the index with largest value smaller than target u distance
var low = 0, high = il - 1, comparison;
while ( low <= high ) {
i = Math.floor( low + ( high - low ) / 2 ); // less likely to overflow, though probably not issue here, JS doesn't really have integers, all numbers are floats
comparison = arcLengths[ i ] - targetArcLength;
if ( comparison < 0 ) {
low = i + 1;
continue;
} else if ( comparison > 0 ) {
high = i - 1;
continue;
} else {
high = i;
break;
// DONE
}
}
i = high;
//console.log('b' , i, low, high, Date.now()- time);
if ( arcLengths[ i ] === targetArcLength ) {
var t = i / ( il - 1 );
return t;
}
// we could get finer grain at lengths, or use simple interpolatation between two points
var lengthBefore = arcLengths[ i ];
var lengthAfter = arcLengths[ i + 1 ];
var segmentLength = lengthAfter - lengthBefore;
// determine where we are between the 'before' and 'after' points
var segmentFraction = ( targetArcLength - lengthBefore ) / segmentLength;
// add that fractional amount to t
var t = ( i + segmentFraction ) / ( il -1 );
return t;
};
function checkMotionPath(motionPath) {
if (!Array.isArray(motionPath)) return false;
for (let i = 0, l = motionPath.length; i < l; i++) {
let controls = motionPath[i];
if (!Array.isArray(controls) || controls.length !== 6) return false;
}
return true;
}
function sampleMotionPaths (motionPaths, data, duration, fps, target) {
function createControlPoints(array) {
if (array instanceof cc.Vec2) {
return {
in: array,
pos: array,
out: array
};
}
else if (Array.isArray(array) && array.length === 6) {
return {
in: v2(array[2], array[3]),
pos: v2(array[0], array[1]),
out: v2(array[4], array[5])
};
}
return {
in: cc.Vec2.ZERO,
pos: cc.Vec2.ZERO,
out: cc.Vec2.ZERO
};
}
let values = data.values = data.values.map(function (value) {
if (Array.isArray(value)) {
value = value.length === 2 ? cc.v2(value[0], value[1]) : cc.v3(value[0], value[1], value[2]);
}
return value;
});
if (motionPaths.length === 0 || values.length === 0) {
return;
}
let motionPathValid = false;
for (let i = 0; i < motionPaths.length; i++) {
let motionPath = motionPaths[i];
if (motionPath && !checkMotionPath(motionPath)) {
cc.errorID(3904, target ? target.name : '', 'position', i);
motionPath = null;
}
if (motionPath && motionPath.length > 0) {
motionPathValid = true;
break;
}
}
if (!motionPathValid) {
return;
}
if (values.length === 1) {
return;
}
var types = data.types;
var ratios = data.ratios;
var newValues = data.values = [];
var newTypes = data.types = [];
var newRatios = data.ratios = [];
function addNewDatas (value, type, ratio) {
newValues.push(value);
newTypes.push(type);
newRatios.push(ratio);
}
// ensure every ratio section's length is the same
var startRatioOffset = 0;
var EPSILON = 1e-6;
var newType = DynamicAnimCurve.Linear;
// do not need to compute last path
for (var i = 0, l = motionPaths.length; i < l-1; i++) {
var motionPath = motionPaths[i];
var ratio = ratios[i];
var nextRatio = ratios[i + 1];
var betweenRatio = nextRatio - ratio;
var value = values[i];
var nextValue = values[i + 1];
var type = types[i];
var results = [];
var progress = startRatioOffset / betweenRatio;
var speed = 1 / (betweenRatio * duration * fps);
var finalProgress;
if (motionPath && motionPath.length > 0) {
var points = [];
points.push(createControlPoints(value));
for (var j = 0, l2 = motionPath.length; j < l2; j++) {
var controlPoints = createControlPoints(motionPath[j]);
points.push(controlPoints);
}
points.push(createControlPoints(nextValue));
// create Curve to compute beziers
var curve = new Curve(points);
curve.computeBeziers();
// sample beziers
var progresses = curve.progresses;
while ( 1 - progress > EPSILON) {
finalProgress = progress;
finalProgress = computeRatioByType(finalProgress, type);
var pos, bezier, normal, length;
if (finalProgress < 0) {
bezier = curve.beziers[0];
length = (0 - finalProgress) * bezier.getLength();
normal = bezier.start.sub(bezier.endCtrlPoint).normalize();
pos = bezier.start.add(normal.mul(length));
}
else if (finalProgress > 1) {
bezier = curve.beziers[curve.beziers.length - 1];
length = (finalProgress - 1) * bezier.getLength();
normal = bezier.end.sub(bezier.startCtrlPoint).normalize();
pos = bezier.end.add(normal.mul(length));
}
else {
var bezierIndex = binarySearch(progresses, finalProgress);
if (bezierIndex < 0) bezierIndex = ~bezierIndex;
finalProgress -= bezierIndex > 0 ? progresses[bezierIndex - 1] : 0;
finalProgress = finalProgress / curve.ratios[bezierIndex];
pos = curve.beziers[bezierIndex].getPointAt(finalProgress);
}
results.push(pos);
progress += speed;
}
}
else {
while ( 1 - progress > EPSILON) {
finalProgress = progress;
finalProgress = computeRatioByType(finalProgress, type);
results.push(value.lerp(nextValue, finalProgress));
progress += speed;
}
}
newType = type === 'constant' ? type : DynamicAnimCurve.Linear;
for (var j = 0, l2 = results.length; j < l2; j++) {
var newRatio = ratio + startRatioOffset + speed * j * betweenRatio;
addNewDatas(results[j], newType, newRatio);
}
if (Math.abs(progress - 1) > EPSILON) // progress > 1
startRatioOffset = (progress - 1) * betweenRatio;
else
startRatioOffset = 0;
}
if (ratios[ratios.length - 1] !== newRatios[newRatios.length -1]) {
addNewDatas(values[values.length - 1], newType, ratios[ratios.length - 1]);
}
}
if (CC_TEST) {
cc._Test.sampleMotionPaths = sampleMotionPaths;
}
module.exports = {
sampleMotionPaths: sampleMotionPaths,
Curve: Curve,
Bezier: Bezier
};